Separation of potentially harmful environmental pollutants, specifically gases, is increasingly important. As an example, carbon monoxide is a poisonous gas produced as a by-product during the combustion of fossil fuels. With the growth of fossil fuel consumption, there remains an ever increasing need for carbon monoxide separation.
Recent efforts have focused on the preparation of materials which adsorb or complex with carbon monoxide to clean the gas stream containing that compound. For example, Japanese Patent No. 84-69206; and U.S. Pat. No. 4,099,984 to Christianson et al. proposes various metal halide materials which complex or adsorb with CO. Nonetheless, in spite of these efforts, there remains a need to monitor the actual adsorption or complexing of the carbon monoxide.
Monitoring of CO has traditionally been difficult due to the odorless and colorless nature of the gas. It would be especially desirable to signal when potentially dangerous levels of the gas are present. Moreover, in gas separation applications, monitoring the system so as to signal when the separation of the gas is near end to allow for regeneration of the adsorbing materials for subsequent use would be advantageous.